you use the perfect words to describe the sea; things like 'beating, brew, ebb, shell,' and 'swell' especially, etc etc... and the idea of the pearl is an excellent way to wrap it up. very well done, a pleasant and interesting poem ^^

~Susurrus

ah, what a rhyme scheme!

i really like your idea and the imagery is really well done!
theres just a few problems with the rhyme scheme/sonnet form.
lines 1&3, 5&7 dont rhyme 1&3 dont rhyme at all and 5& 7 is a near rhyme...
along with fingers and linger-i dont know if that would work
plus, you're missing your rhyming couplet